1. Field of the Invention
The present invention relates to a rotor and a motor having the same.
2. Discussion of Related Art
Generally, a vehicle includes a starter motor which drives an engine and an alternator which generates electricity using a rotational force of the engine. The starter motor has an ignition switch which is connected to a power supply of a battery by an operation of a driver when the vehicle is started, power is supplied to the starter motor through the connection, and the vehicle is started by the engine being rotated by a driving force generated by the starter motor.
In comparison, an alternating current (AC) power is generated by the alternator being connected to a driving unit of the engine to rotate a rotor while a magnetic field is formed by a driving force of the engine, and thus the battery is charged using a rectifier etc.
Since both of the starter motor and the alternator are configured in a structure having a stator and a rotor, structures of the starter motor and the alternator are very similar to each other and can be operated as a power generator or a motor depending on whether a force or power is applied.
Recently, a belt driven starter generator (BSG) structure capable of functioning as a starter motor and an alternator with a single structure is actively being studied.
Meanwhile, a wound rotor synchronous motor is a motor having teeth which protrude from an outer circumferential surface of a rotor core and around which a coil is wound. The wound motor synchronous motor has not only been mainly used as a generator but has also been recently proposed as a form of a traction motor since a development of a rare earth-free motor has been spotlighted.
However, a motor has to increase the number of wound coils or current to increase torque thereof. However, in the case of a BSG, there is a problem in that an increase in a torque of the motor is limited because there is a limit in increasing the number of wound coils due to spatial constraints and in increasing a current due to a current limit.
Also, an inlet through which a nozzle is inserted into a winding space is formed between teeth of a rotor that are adjacent to each other to perform winding, and coils wound through the inlet may deviate therefrom, and thus the space should be closed with a separate member after the winding. Therefore, there is a problem in which manufacturing time and manufacturing costs are increased.
Also, there is a problem in which manufacturing components and the number of manufacturing processes are increased because a separate fan is pressed and mounted at an upper part of a rotor to cool heat generated in a coil wound around the rotor.